Analysts ask: Did Samsung cut corners in shipping Note7 replacements?

When the serial number for the phone was run through a Samsung recall eligibility checker online, a message responded that it was not one of the units affected by the recall, according to reports. Green also said the phone was at about 80% battery capacity and that he has used only a wireless charger since receiving the device.

Green could not be reached for additional details, including whether he had successfully turned the phone completely off before putting it in his pocket.

No one was injured in the evacuation of the jet, and customers were directed to other flights, Southwest said in a statement.

Samsung also issued a statement that said it will verify if Green's phone was a replacement: "Until we are able to retrieve the device, we cannot confirm that this incident involves the new Note7. We are working with authorities and Southwest to recover the device and confirm the cause. Once we have examined the device we will have more information to share."

Only last week, Samsung assured the public its replacement Note7 smartphones were safe. It was an attempt to reassure customers who were concerned about reports from South Korea, China and the U.S. that replacement devices were running too hot.

"We would like to reassure everyone that the new Note7 phones are operating properly and pose no safety concerns," the company said on Sept. 30. "In normal conditions, all smartphones may experience temperature fluctuations."

Some analysts have commended Samsung for updating the public regularly on its global recall of Note7s, but are nonetheless concerned by the latest reports that a replacement unit could burn so hot that it would begin smoking and burn through its case.

"I have been monitoring some claims in China of the...Note7 with the 'good' battery catching fire, but not a single one of these incidents has been traced back to Samsung," said Patrick Moorhead, an analyst at Moor Insights & Strategy. "So, for right now, we all need complete information before jumping to any conclusions. If it is verified that the phone is, in fact, a replacement phone, Samsung will have some major problems on its hands."

Samsung first issued its own recall of the original Note7 globally on Sept. 2 and the U.S. Consumer Product Safety Commission (CPSC) officially recalled 1 million devices in the U.S. on Sept. 15.

At the time, the CPSC said it had received 92 reports of batteries overheating in the original devices, including 26 reports of burns and 55 reports of property damage.

After Wednesday's Southwest evacuation, the CPSC issued a statement from its chairman, Elliot Kay, that the agency is "moving expeditiously" to investigate by contacting Green, Samsung and the Federal Aviation Administration. Kay reiterated that Note7 customers who haven't obtained a replacement device need to power them down.